Merge branch 'move-ld_abs-to-native-BPF'

Daniel Borkmann says:

====================
This set simplifies BPF JITs significantly by moving ld_abs/ld_ind
to native BPF, for details see individual patches. Main rationale
is in patch 'implement ld_abs/ld_ind in native bpf'. Thanks!

v1 -> v2:
  - Added missing seen_lds_abs in LDX_MSH and use X = A
    initially due to being preserved on func call.
  - Added a large batch of cBPF tests into test_bpf.
  - Added x32 removal of LD_ABS/LD_IND, so all JITs are
    covered.
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

3 files changed, 37 insertions, 4 deletions

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 68ecdb4eea09..0e00a13ff01b 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -235,6 +235,8 @@ struct bpf_verifier_ops {
 				struct bpf_insn_access_aux *info);
 	int (*gen_prologue)(struct bpf_insn *insn, bool direct_write,
 			    const struct bpf_prog *prog);
+	int (*gen_ld_abs)(const struct bpf_insn *orig,
+			  struct bpf_insn *insn_buf);
 	u32 (*convert_ctx_access)(enum bpf_access_type type,
 				  const struct bpf_insn *src,
 				  struct bpf_insn *dst,
@@ -714,8 +716,6 @@ extern const struct bpf_func_proto bpf_ktime_get_ns_proto;
 extern const struct bpf_func_proto bpf_get_current_pid_tgid_proto;
 extern const struct bpf_func_proto bpf_get_current_uid_gid_proto;
 extern const struct bpf_func_proto bpf_get_current_comm_proto;
-extern const struct bpf_func_proto bpf_skb_vlan_push_proto;
-extern const struct bpf_func_proto bpf_skb_vlan_pop_proto;
 extern const struct bpf_func_proto bpf_get_stackid_proto;
 extern const struct bpf_func_proto bpf_get_stack_proto;
 extern const struct bpf_func_proto bpf_sock_map_update_proto;
diff --git a/include/linux/filter.h b/include/linux/filter.h
index b7f81e3a70cb..da7e16523128 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -47,7 +47,9 @@ struct xdp_buff;
 /* Additional register mappings for converted user programs. */
 #define BPF_REG_A	BPF_REG_0
 #define BPF_REG_X	BPF_REG_7
-#define BPF_REG_TMP	BPF_REG_8
+#define BPF_REG_TMP	BPF_REG_2	/* scratch reg */
+#define BPF_REG_D	BPF_REG_8	/* data, callee-saved */
+#define BPF_REG_H	BPF_REG_9	/* hlen, callee-saved */
 
 /* Kernel hidden auxiliary/helper register for hardening step.
  * Only used by eBPF JITs. It's nothing more than a temporary
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a3a495052511..93d5a4eeec2a 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1802,6 +1802,30 @@ union bpf_attr {
  * 	Return
  * 		a non-negative value equal to or less than size on success, or
  * 		a negative error in case of failure.
+ *
+ * int skb_load_bytes_relative(const struct sk_buff *skb, u32 offset, void *to, u32 len, u32 start_header)
+ * 	Description
+ * 		This helper is similar to **bpf_skb_load_bytes**\ () in that
+ * 		it provides an easy way to load *len* bytes from *offset*
+ * 		from the packet associated to *skb*, into the buffer pointed
+ * 		by *to*. The difference to **bpf_skb_load_bytes**\ () is that
+ * 		a fifth argument *start_header* exists in order to select a
+ * 		base offset to start from. *start_header* can be one of:
+ *
+ * 		**BPF_HDR_START_MAC**
+ * 			Base offset to load data from is *skb*'s mac header.
+ * 		**BPF_HDR_START_NET**
+ * 			Base offset to load data from is *skb*'s network header.
+ *
+ * 		In general, "direct packet access" is the preferred method to
+ * 		access packet data, however, this helper is in particular useful
+ * 		in socket filters where *skb*\ **->data** does not always point
+ * 		to the start of the mac header and where "direct packet access"
+ * 		is not available.
+ *
+ * 	Return
+ * 		0 on success, or a negative error in case of failure.
+ *
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -1871,7 +1895,8 @@ union bpf_attr {
 	FN(bind),			\
 	FN(xdp_adjust_tail),		\
 	FN(skb_get_xfrm_state),		\
-	FN(get_stack),
+	FN(get_stack),			\
+	FN(skb_load_bytes_relative),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call
@@ -1932,6 +1957,12 @@ enum bpf_adj_room_mode {
 	BPF_ADJ_ROOM_NET,
 };
 
+/* Mode for BPF_FUNC_skb_load_bytes_relative helper. */
+enum bpf_hdr_start_off {
+	BPF_HDR_START_MAC,
+	BPF_HDR_START_NET,
+};
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */